Swivel caster



SWIVEL CASTER Filed June 16. 1230 Patented Nov. 1, 1932 UNITED STATES SEIBERT W. CHESNUTT, 0F KANSAS CITY, MISSOURI SWIVEL Application filed .Tune 16,

The primary object ofk this invention is to provide an improved construction for a double ball bearing swivel caster so designed as to be quick act-ing, strong and durable, and easily and economically manufactured.

Another object of the invention is to provide an improved arrangement of the swiveling parts of a cast-er, whereby 'the assembly will Vprovide a chamber adapted to contain "lubricating material designed to add to the eiiiciency and lasting'qualities of the swivelin@ parts; f

tStill another objeotof the invention is to y provide an improved construction for swivel casters which may be made as a stem caster or a t-op yplate caster, in any suitable size or of any suitable material for various purposes. With these and other yobjects in viewfmy invention consists in the construction, ar-

rangement and combination of the various parts of mydevice, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawing, in VAwhich:

Figure 1 is a vertical sectional view of a stemtype of swivel caster, embodying my inven-tion. 4 Figure 2 is a horizontal section on the line 2-2 of vFigure 1, showing the upperrow of bearing balls and the members which constitute the ball'race.

AFigure 3 is a horizontaly section on the line 3 3 of Figure 1, showing the lower row of l Aballs and the members which constitute the ball race', together with a grease retaining gasket. Y

Figure 4 Vis a vertical section through the Q load bearing portions of a'plate type of caster, vembodying my invention.

CASTEB,

1930. Serial No. 461,543.

friction bearings, and having either a meper'margin with a horizontal portion 22 of annular form having a circular opening at its center defined by a downwardly extending flange 24.

The load bearing portion of the caster includes a circular top plate 26 provided with a downwardly extending flange 2S at its outer margin forming a continuation of and spaced slightly above the cylindrical shell 10.

Mounted within the peripheral flange 28 of the top plate is an annular ball race member including a horizontal portion 30 resting 0n the horizontal portion 22 of the shell, and an upstanding portion 82 arranged concentrically of and spaced slightly within the downturned flange 28 of the top plate. The

vhorizontal portion 30 of the ball race is shaped to tit smoothly and snugly against the upper surface of the horizontal portion 22 of the shell and when the parts are assembled these members are held firmly and rigidly together. The horizontal portion 30 of the ball race preferably is formed at its inner margin with a slightly downturned lip 34 overhangingthe inner edge of the horizontal portion 22 of the shell.

TWithin the ball race member just described are mounted la series of bearing balls 36 which contact with the upper surface of the horizontal portion 30 and with the inner surface of the upstanding portion 32, and also Contact with the lower surface of the top plate 26.

A retaining plate 38 is mounted within the shell 10 and is formed at its outer margin with an upstanding flange 4() which is spaced approximately mid-way between the wall of the shelland its inner down-turned flange 24. A series of bearing balls 42 are mounted on the retaining plate 38 and between the upturned flange 40 thereof and the downturned flange 24 Vof the shell, said balls also contactin with the lower surface of the horizonta part 22 of the shell. i

Between the top plate 26 and retaining plate 28 ismounted a spacing sleeve 44 and through said sleeve a securing member such as 'a stem 46 is mounted. Thestem 46 is vformed with a head or upset portion 48 at its lo'wer end engaging the lower surface -of the retaining plate 38 and is also formed between its ends with a shoulder en aging the upper surface of the top plate w ereby the parts are heldi in assembled relation. The upper, portion of the stem 46 may be employed inthe ordinary Ymanner for attac 'ng the caster te a load object.

The lower portion Yof the spacing sleeve 44 preferably lits snuglly about the stern 46, but the u per portion t ereof is flared outwardly and orms anY inner bearing for the upper row of balls 36. The balls 36 preferably are of lar `.r diameter and reater strength than the ba s 42 as they are' esign'ed to carry the greater portion of thelload.

The two annular rows of balls 36 and 42 provide ample anti-friction means for swivelly supporting the load bearing and wheel carryln portions of the caster relative to each o er. Y

Itis desirableY to provide means for constantly lubricating the bearing-balls 36 and 42 and I have so constructed the swivelin f parts thatllubricating grease may be moiinte within the annule.;` c amber defined at its inner margirrby the spacing sleeve 44 and at its outer margin by the cylindrical shell 10 and c lindricaI flange 28. This chamber is Yrenered grease-tight by an annular gasket 52 mounted between the shell Y1() and upstanding flange 40 of the retaining plate and by an annular gasket 54 mounted between the horizontal ortion 22 the shell and the lower edge o the peripheral flange 28 the top plate. The annular chamber thus formed may be supplied with ease or hard oil which will continue to lu ricate the bearing balls 42 and 36 and other movable parts over a 1011 period of use and thus add greatly to the e ciency and lasting qualities of theY Swiveling parts.

The lower part of the shell 10 is further closed by a circular concaved plate 56 which has its edges in engagement with the lower edge of the gasket 52 Vand serves to hold said gasket in place and also to further assist in preventing the escape of lubricant from theY grease chamber. The concaved plate 56 is fitted tightly within the lower end of the shell 10 and forms an imperforate closure for the bottom of the swiveling chamber and assembly.

In case it is desired to employ my improvements in a plate type of caster, an addltional attaching plate 58 would be mounted on the top plate 26, this attaching plate being of larger dimension than the top plate, and being provided with suitable apertures such as 6() for receiving screws or bolts to attach the caster to the lower surface of arload obg'ect.

In this construction the stem 46 is replaced by a rivet 62 having a head 64 at its lower end engaging the lower surface of the retaining member 38 and at its upper end a head 66 which preferably is countersunk in the upper surface of the attaching plate 58. The other parts of the caster may be identical with the parts previously described.

My improved swivel caster is capable of being made in many diierent sizes and from different materials to adapt it for different purposes. It is so constructed as to induce easy relative turning of the swiveling parts and the provision for a grease-tight swiveling chamber is of great advantage in keeping the caster in eflicient condition over a lon period of use.

Sgome changes may be made in the construction and arrangement of the parts of my device without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or use of mechanical equivalents, which may be reasonably included Within their scope.

I claim as my invention z- 1. A swivel caster comprising a wheelcarrying member including a downwardly opening cylindrical part, a load-bearing member having a downwardly opening cylindrical part arranged above the first named member and communicating centrally with the interior thereof, an imperforate closing plate mounted in the lower end of the cylindrical part of the wheel-carrying member, and an annular gasket mounted between the cylindrical part of the wheel-carrying member and the open lower end of the cylindrical part of the load-bearing member.

2. A swivel caster comprising a wheelcarrying member including a downwardly opening cylindrical part, a load-bearing member having a downwardly opening cylindrical part arranged above the first named member and communicating centrally with the interior thereof, an imperforate closing plate mounted in the lower end of the cylindrical part of the wheel-carryin member, an annular gasket mounted wlthin and against the wall of the cylindrical part'of the wheel-carrying member and contacting with the peripheral portion of said closing plate, and an annular gasket mounted between the cylindrical part of the wheelcarrying member and the open lower end of the cylindrical part of the load-bearing member.

Tft

3. A swivel caster comprising a wheelcarrying member including a downwardly opening cylindrical part, a load-bearing member having a downwardly opening cylindrical part arranged above the iirst named member and communicating centrally with the interior thereof, an imperforate closing plate mounted in the lower end of the cylindrical part of the wheel-carrying member, an upwardly opening cup-shaped retaining plate mounted in the cylindrical part of the wheel-carrying member beneath the central communication with said load-bearing member, an annular gasket mounted snugly between the wall of said cup-shaped retaining member and the wall of the cylindrical part of the wheel-carrying member in engagement with the peripheral portion of the closing plate, and an annular gasket mounted between the cylindrical part of the wheelcarrying member and the open lower end of :ghe cylindrical part of the load-bearing mem- 4. In a swivel caster, a cylindrical loadbearing member, a. downwardly opening cylindrical wheel-carrying member swivelly attached thereto, an annular gasket mounted between the peripheral portions of said cylindrical members, a retaining plate mounted within the cylindrical wheel-carrying member, an annular gasket mounted between the peripheral portion of said retaining plate and the wall of said wheel-carrying member, and an imperforate closing plate mounted beneath said retaining plate and snugly fitted within the wall of said cylindrical wheelcarrying member for forming a chamber for lubricant.

5. A swivel caster comprising a cylindrical load-bearing member formed with a flat horizontal central apertured portion and an outer right-angled downturned flange; a wheelcarrying member formed with wheel-supporting portions, a cylindrical perpendicular shell, and a flat, horizontal top with a central right-angled, downturned flange, the inner angles forming bearing surfaces; a cupshaped bearing member formed with a horizontal portion fitting snugly the upper surface of the horizontal portion of said wheelcarrying member, and an outer right-angled upturned flange spaced inside said load-carrying member; an annular series of bearing balls within said cup-shaped bearing memj ber and engaging beneath the horizontal portion at the top of said load-bearing member; a retaining member or keeper located within and spaced from said wheel-carrying member, formed with a central apertured horizontal portion and with an outer right-angled upturned flange, the inner angles forming bearing surfaces; a spacing and bearing member, centrally located within the assembly of said members, contacting the under surface of the G5 horizontal portion of said load-bearing member and the upper surface of the horizontal portion of said retaining member or keeper, formed with its lower portion spaced within the central portions of said wheel-carrying member and said cup-shaped bearing member, its upper portion aring outward and upward and then extending perpendicularly, and this perpendicular portion acting as an inner bearing surface for said bearing balls; a second annular series of bearing balls located between the coacting bearing surfaces of said wheel-carrying member and said retaining plate or keeper; and a securing member eX- tending through the central opening of the assembly and holding said members rigidly in position.

SEIBERT W. CHESNUTT.

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